Determination of theD2parameter for (d,t) reactions

Measurements of the tensor analyzing powers have been obtained for ($\overrightarrow{d},t$) reactions on ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{118}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{119}{}_{}{}^{}\mathrm{Sn}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ for deuteron energies both above and below the Coulomb barrier. The measurements are sensitive to the presence of $D$-state components in the triton wave function and allow the determination of a parameter $D_2$. This parameter is a measure of the importance of triton wave function components in which one neutron moves with orbital angular momentum $L=2\mathrm{}$ relative to the deuteron center of mass. Values of $D_2$ are extracted from the tensor analyzing power measurements by making use of distorted-wave Born approximation calculations. Analysis of the sub-Coulomb measurements leads to $D_2=-0.279\mathrm{}\pm 0.012$ ${\mathrm{fm}}^2$, which is somewhat larger in magnitude than recent theoretical predictions.